Those who Christ died for?Those who Christ died for were chosen in Christ and accepted in Him before the foundation of the world Eph 1:4-6
4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
5 Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,
6 To the praise of the glory of his grace, wherein he hath made us accepted in the beloved.
(your Calvinism is showing)
Didn't Christ die for the whole world?
1 Timothy 4:10 NIV
That is why we labor and strive, because we have put our hope in the living God,
who is the Savior of all people, and especially of those who believe.